30320 bearing: complete specifications & equivalents
The 30320 is a ISO 355 radial bearing sized 100 x 215 x 51.5 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 100 mm |
| Outer diameter D | 215 mm |
| Width B | 51.5 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 431 kN |
| Basic static load rating C0 | 490 kN |
| Fatigue load limit Pu | 53 kN |
| Reference speed (thermal) | 2400 rpm |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 7950 g |
| Manufacturer designation | SKF 30320 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 30300-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 2.028 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 57.5 mm |
| Smallest bore in 30300-series | 15 mm |
| Largest outer diameter in 30300-series | 500 mm |
| Width range across 30300-series | 14.25–105 mm |
| Bore position in 30300-series (smallest first) | 19 of 32 |
| Bore above smallest 30300-series size | 85 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30320 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 355 boundary-dimension envelope; brand-specific OEM equivalents (NSK/FAG/NTN) pending multi-source data. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 30320 model number is decoded
The SKF 30320 is a 100×215×51.5 mm single-row tapered roller bearing — the heavy-OD section entry in the 30300 series, with an asymmetric raceway cut for thrust capacity and separable mounting.Numbering ties the bearing to its envelope: 30320 means tapered-roller type 3, heavy-OD section series 03, 100 mm bore — which is why the 215×51.5 mm outline swaps dimensionally with other ISO 355 bearings of the same code. The SKF catalogue adds the ISO 355 dimension-series code after the bare number (e.g. 2GB); it is the dimensional series, not a separate part number. The 53 kN Pu figure feeds the adjusted-life equation at contaminated or partial-film conditions, and the 1.14 C0/C balance shows this execution is tuned to thrust-heavy combined loads rather than pure radial running. Because the contact line is tapered, one 30320 reacts thrust in a single direction; bidirectional shafts need an O or X pair, and a rotating cone on a 100 mm shaft typically takes a k5 seat with an H7 housing bore.
Typical equipment & failure modes
Common applications
- construction machinery drives
- marine deck machinery shafts
- heavy industrial gearboxes and speed reducers
- large process pump and compressor shafts
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- uneven load sharing in a pair when spacer faces are not parallel to the bore
- thermal preload runaway in an O-arrangement pair when inner-ring heat expands the setting
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- mounting score marks when the cone is cocked over the shaft keyway or a burr
Selection pitfalls — read before you substitute
- Mount the 100 mm bore 30320 by induction heating of the cone (max 120 °C — the pressed-steel cage sets the ceiling, not the steel); driving it home through the cup or rollers brinells the tapered raceway.
- The 303 series at 100 mm bore (215×51.5 mm) carries a larger OD and higher capacity than 30220 at the same bore; the bigger section runs hotter, so re-check the 3,200 r/min speed ceiling and shoulder diameters before substituting.
- At the 431 kN rating of 30320, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 3,200 r/min speed end and heavier preload only where moment stiffness dominates.
- At the 431 kN rating of 30320, preload class changes stiffness by tens of percent but also heat generation; select light preload for the 3,200 r/min speed end and heavier preload only where moment stiffness dominates.
- Shaft and housing fillets must clear the bearing chamfer so the 51.5 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 431/490 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of 30320 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30320 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30320?
The SKF 30320 is a single-row tapered roller bearing with 100 mm bore, 215 mm outer diameter and 51.5 mm width (3.937 × 8.465 × 2.028 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 431 kN, C0 490 kN, fatigue load limit Pu 53 kN, reference speed 2,400 r/min, limiting speed 3,200 r/min, mass about 7950 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30320 bore code work?
The last two digits of 30320 are bore code 20, so 20 × 5 = 100 mm bore. The 215 mm OD and 51.5 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30320 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 03 is the ISO 355 series (heavy-OD section). The SKF catalogue lists the ISO 355 dimension-series code after the bare number. A steeper-contact-angle variant (B suffix) is a different order number and is not interchangeable with the basic execution.
Can a single 30320 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 30320 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 30320 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB on 2026-09-26. Read our editorial & correction policy.